<?php
/**
 * zip压缩与解压类
 * 
 * 使用方法：
 * 
include('dwZip.php');
$zip=new dwZip;
//压缩
$zip->zip('./','test.zip');
//解压缩
$zip->unzip('test.zip','./data/');
 */
class dwZip{
	
	protected $datasec = array();
	protected $ctrl_dir = array();
	protected $eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00";
	protected $old_offset = 0;
	
	protected $total_files = 0;
	protected  $total_folders = 0; 
	
	public function zip($dir='./', $zip_filename='dw.zip'){
    	if (function_exists('gzcompress')) { 
			$filelist = $this->getFileList($dir);

			if (count($filelist)>0) {
				foreach($filelist as $filename) {
					if (is_file($filename)){
						$fd = fopen ($filename, "r");
						$content = fread($fd, filesize ($filename));
						fclose ($fd);
						$this->addFile($content, $filename);
					}
				}
				$out = $this->file();
				$fp = fopen($zip_filename, "w");
				fwrite($fp, $out, strlen($out));
				fclose($fp);
				return true;
			}
		} 

		return false;
	}


	 public function unzip($zip_filename='dw.zip', $dir='./') {
			$index = array(-1);
			$ok = 0;
			$zip_fp = @fopen($zip_filename,'rb');
			if(!$zip_fp)
				return false;
				
			$cdir = $this->readCentralDir($zip_fp,$zip_filename);
			$pos_entry = $cdir['offset'];
			
			for($i=0; isset($index[$i]);$i++){
				if(intval($index[$i])!=$index[$i]||$index[$i]>$cdir['entries'])
				return false;
			}
			for ($i=0; $i<$cdir['entries']; $i++){
				 @fseek($zip_fp, $pos_entry);
				 $header = $this->readCentralFileHeaders($zip_fp);
				 $header['index'] = $i;
				 $pos_entry = ftell($zip_fp);
				 @rewind($zip_fp); 
				 fseek($zip_fp, $header['offset']);
				 if(in_array("-1",$index)||in_array($i,$index))
					$stat[$header['filename']]=$this->extractFile($header, $dir, $zip_fp);
			}
			
			fclose($zip_fp);
			return $stat;
	 }
	 
	 
	 
	protected function getFileList($dir) 
	{
    	$file=array();
		if (file_exists($dir)) 
		{
		
      		if( substr( $dir, -1 ) != "/" ) 
			{
    			$dir .= "/";
   			}

			
      		$dh = opendir($dir);
      		while($files = readdir($dh)) {
        		if (($files!=".")&&($files!="..")) 
				{
          			if (is_dir($dir.$files)) 
					{
            			$file = array_merge($file, $this -> getFileList( $dir.$files ));
          			}
            		else $file[]= $dir.$files;
        		}
      		}
      		closedir($dh);
    	}
		$file[] = '';
    	return $file;
	}

	protected function unix2DosTime($unixtime = 0) {
    	$timearray = ($unixtime == 0) ? getdate() : getdate($unixtime); 
   		if ($timearray['year'] < 1980) {
		  $timearray['year'] = 1980;
		  $timearray['mon'] = 1;
		  $timearray['mday'] = 1;
		  $timearray['hours'] = 0;
		  $timearray['minutes'] = 0;
		  $timearray['seconds'] = 0;
   		} 
    	return (($timearray['year'] - 1980) << 25) | ($timearray['mon'] << 21) | ($timearray['mday'] << 16) |
    ($timearray['hours'] << 11) | ($timearray['minutes'] << 5) | ($timearray['seconds'] >> 1);
	} 

	protected function addFile($data, $name, $time = 0) {
		$name = str_replace('\\', '/', $name); 
		$dtime = dechex($this->unix2DosTime($time));
		$hexdtime = '\x' . $dtime[6] . $dtime[7]
		. '\x' . $dtime[4] . $dtime[5]
		. '\x' . $dtime[2] . $dtime[3]
		. '\x' . $dtime[0] . $dtime[1];
		eval('$hexdtime = "' . $hexdtime . '";');
		
		$fr = "\x50\x4b\x03\x04";
		$fr .= "\x14\x00"; // ver needed to extract
		$fr .= "\x00\x00"; // gen purpose bit flag
		$fr .= "\x08\x00"; // compression method
		$fr .= $hexdtime; // last mod time and date
		
		// "local file header" segment
		$unc_len = strlen($data);
		$crc = crc32($data);
		$zdata = gzcompress($data);
		$c_len = strlen($zdata);
		$zdata = substr(substr($zdata, 0, strlen($zdata) - 4), 2); // fix crc bug
		$fr .= pack('V', $crc); // crc32
		$fr .= pack('V', $c_len); // compressed filesize
		$fr .= pack('V', $unc_len); // uncompressed filesize
		$fr .= pack('v', strlen($name)); // length of filename
		$fr .= pack('v', 0); // extra field length
		$fr .= $name;
		
		// "file data" segment
		$fr .= $zdata;
		
		// "data descriptor" segment (optional but necessary if archive is not
		// served as file)
		$fr .= pack('V', $crc); // crc32
		$fr .= pack('V', $c_len); // compressed filesize
		$fr .= pack('V', $unc_len); // uncompressed filesize
		
		// add this entry to array
		$this -> datasec[] = $fr;
		$new_offset = strlen(implode('', $this->datasec));
		
		// now add to central directory record
		$cdrec = "\x50\x4b\x01\x02";
		$cdrec .= "\x00\x00"; // version made by
		$cdrec .= "\x14\x00"; // version needed to extract
		$cdrec .= "\x00\x00"; // gen purpose bit flag
		$cdrec .= "\x08\x00"; // compression method
		$cdrec .= $hexdtime; // last mod time & date
		$cdrec .= pack('V', $crc); // crc32
		$cdrec .= pack('V', $c_len); // compressed filesize
		$cdrec .= pack('V', $unc_len); // uncompressed filesize
		$cdrec .= pack('v', strlen($name) ); // length of filename
		$cdrec .= pack('v', 0 ); // extra field length
		$cdrec .= pack('v', 0 ); // file comment length
		$cdrec .= pack('v', 0 ); // disk number start
		$cdrec .= pack('v', 0 ); // internal file attributes
		$cdrec .= pack('V', 32 ); // external file attributes - 'archive' bit set
		
		$cdrec .= pack('V', $this -> old_offset ); // relative offset of local header
		$this->old_offset = $new_offset;
		
		$cdrec .= $name;
	
		$this->ctrl_dir[] = $cdrec;
	} 

	protected function file() {
		$data = implode('', $this -> datasec);
		$ctrldir = implode('', $this -> ctrl_dir);
		
		return
		$data .
		$ctrldir .
		$this -> eof_ctrl_dir .
		pack('v', sizeof($this -> ctrl_dir)) . 
		pack('v', sizeof($this -> ctrl_dir)) . 
		pack('V', strlen($ctrldir)) .
		pack('V', strlen($data)) . 
		"\x00\x00"; 
	} 

	
	//下面是zip解压部分
	protected  function readFileHeader($zip)
	{
		$binary_data = fread($zip, 30);
		$data = unpack('vchk/vid/vversion/vflag/vcompression/vmtime/vmdate/Vcrc/Vcompressed_size/Vsize/vfilename_len/vextra_len', $binary_data);
		
		$header['filename'] = fread($zip, $data['filename_len']);
		if ($data['extra_len'] != 0) {
		  $header['extra'] = fread($zip, $data['extra_len']);
		} else { $header['extra'] = ''; }
		
		$header['compression'] = $data['compression'];$header['size'] = $data['size'];
		$header['compressed_size'] = $data['compressed_size'];
		$header['crc'] = $data['crc']; $header['flag'] = $data['flag'];
		$header['mdate'] = $data['mdate'];$header['mtime'] = $data['mtime'];
		
		if ($header['mdate'] && $header['mtime']){
		 $hour=($header['mtime']&0xF800)>>11;$minute=($header['mtime']&0x07E0)>>5;
		 $seconde=($header['mtime']&0x001F)*2;$year=(($header['mdate']&0xFE00)>>9)+1980;
		 $month=($header['mdate']&0x01E0)>>5;$day=$header['mdate']&0x001F;
		 $header['mtime'] = mktime($hour, $minute, $seconde, $month, $day, $year);
		}else{$header['mtime'] = time();}
		
		$header['stored_filename'] = $header['filename'];
		$header['status'] = "ok";
		return $header;
	}

	protected  function readCentralFileHeaders($zip){
		$binary_data = fread($zip, 46);
		$header = unpack('vchkid/vid/vversion/vversion_extracted/vflag/vcompression/vmtime/vmdate/Vcrc/Vcompressed_size/Vsize/vfilename_len/vextra_len/vcomment_len/vdisk/vinternal/Vexternal/Voffset', $binary_data);
		
		if ($header['filename_len'] != 0)
		  	$header['filename'] = fread($zip,$header['filename_len']);
		else 
			$header['filename'] = '';
		
		if ($header['extra_len'] != 0)
		  	$header['extra'] = fread($zip, $header['extra_len']);
		else 
			$header['extra'] = '';
		
		if ($header['comment_len'] != 0)
			$header['comment'] = fread($zip, $header['comment_len']);
		else 
			$header['comment'] = '';
		
		if ($header['mdate'] && $header['mtime'])
		{
			$hour = ($header['mtime'] & 0xF800) >> 11;
			$minute = ($header['mtime'] & 0x07E0) >> 5;
			$seconde = ($header['mtime'] & 0x001F)*2;
			$year = (($header['mdate'] & 0xFE00) >> 9) + 1980;
			$month = ($header['mdate'] & 0x01E0) >> 5;
			$day = $header['mdate'] & 0x001F;
			$header['mtime'] = mktime($hour, $minute, $seconde, $month, $day, $year);
		} else {
			$header['mtime'] = time();
		}
		
		$header['stored_filename'] = $header['filename'];
		$header['status'] = 'ok';
		if (substr($header['filename'], -1) == '/')
			$header['external'] = 0x41FF0010;
		return $header;
	}

	protected function readCentralDir($zip,$zip_name){
		$size = filesize($zip_name);
		
		if ($size < 277) $maximum_size = $size;
		else $maximum_size=277;
		
		@fseek($zip, $size-$maximum_size);
		$pos = ftell($zip); $bytes = 0x00000000;
		
		while ($pos < $size){
			$byte = @fread($zip, 1); $bytes=($bytes << 8) | ord($byte);
			if ($bytes == 0x504b0506 or $bytes == 0x2e706870504b0506){ $pos++;break;} $pos++;
		}
		
		$fdata=fread($zip,18);
		
		$data=@unpack('vdisk/vdisk_start/vdisk_entries/ventries/Vsize/Voffset/vcomment_size',$fdata);
		
		if ($data['comment_size'] != 0) 
			$centd['comment'] = fread($zip, $data['comment_size']);
		else 
			$centd['comment'] = '';
		
		$centd['entries'] = $data['entries'];
		$centd['disk_entries'] = $data['disk_entries'];
		$centd['offset'] = $data['offset'];
		$centd['disk_start'] = $data['disk_start'];
		$centd['size'] = $data['size']; 
		$centd['disk'] = $data['disk'];
		
		return $centd;
	}

	protected function extractFile($header,$to,$zip){
		$header = $this->readFileHeader($zip);
		
		if(substr($to,-1)!="/") $to.="/";
		if($to=='./') $to = '';	
		$pth = explode("/",$to.$header['filename']);
		$mydir = '';
		for($i=0;$i<count($pth)-1;$i++){
			if(!$pth[$i]) continue;
			$mydir .= $pth[$i]."/";
			if((!is_dir($mydir) && @mkdir($mydir,0777)) || (($mydir==$to.$header['filename'] || ($mydir==$to && $this->total_folders==0)) && is_dir($mydir)) ){
				@chmod($mydir,0777);
				$this->total_folders ++;
			}
		}
		
		if(strrchr($header['filename'],'/')=='/') return;
			
		isset($header['external'])?'':$header['external']='';
		if (!($header['external']==0x41FF0010)&&!($header['external']==16)){
			if ($header['compression']==0){
				$fp = @fopen($to.$header['filename'], 'wb');
				if(!$fp) return(-1);
				$size = $header['compressed_size'];
			
				while ($size != 0){
					$read_size = ($size < 2048 ? $size : 2048);
					$buffer = fread($zip, $read_size);
					$binary_data = pack('a'.$read_size, $buffer);
					@fwrite($fp, $binary_data, $read_size);
					$size -= $read_size;
				}
				fclose($fp);
				touch($to.$header['filename'], $header['mtime']);
			}else{
				$fp = @fopen($to.$header['filename'].'.gz','wb');
				if(!$fp) return(-1);
				$binary_data = pack('va1a1Va1a1', 0x8b1f, Chr($header['compression']),
				Chr(0x00), time(), Chr(0x00), Chr(3));
				
				fwrite($fp, $binary_data, 10);
				$size = $header['compressed_size'];
			
				while ($size != 0){
					$read_size = ($size < 1024 ? $size : 1024);
					$buffer = fread($zip, $read_size);
					$binary_data = pack('a'.$read_size, $buffer);
					@fwrite($fp, $binary_data, $read_size);
					$size -= $read_size;
				}
			
				$binary_data = pack('VV', $header['crc'], $header['size']);
				fwrite($fp, $binary_data,8); fclose($fp);
		
				$gzp = @gzopen($to.$header['filename'].'.gz','rb') or die("failed");
				if(!$gzp) return(-2);
				$fp = @fopen($to.$header['filename'],'wb');
				if(!$fp) return(-1);
				$size = $header['size'];
			
				while ($size != 0){
					$read_size = ($size < 2048 ? $size : 2048);
					$buffer = gzread($gzp, $read_size);
					$binary_data = pack('a'.$read_size, $buffer);
					@fwrite($fp, $binary_data, $read_size);
					$size -= $read_size;
				}
				fclose($fp); gzclose($gzp);
			
				touch($to.$header['filename'], $header['mtime']);
				@unlink($to.$header['filename'].'.gz');
				
			}
		}
		
		$this->total_files ++;
		return true;
	}
}
?>